Pinellas Site Profile Review

Status Report and Action Items 

Following the Work Group Meeting

Held on March 1, 2016

John Stiver

SC&A, Inc.

Contractor to:

Advisory Board on Radiation and Worker Health

Centers for Disease Control and Prevention

March 23, 2016
Background

• Original Pinellas technical basis documents (TBDs) prepared in the 

2005–2006 timeframe.

• SC&A Site Profile review completed September 2006 – 11 primary 

issues and 8 secondary issues were identified.

• Subsequently, 6 Work Group (WG) meetings and 1 set of worker 

interviews:

– June 11, 2008 WG meeting

– June 11, 2009 WG meeting

– October 13, 2011 WG meeting

– January 24–25, 2012 – Classified worker interviews – FBI building, Tampa Florida

– November 19, 2012 WG teleconference meeting

– February 11, 2016 WG teleconference meeting (stable metal tritide [SMT] model 

reviewed)

– March 1, 2016 WG teleconference meeting (remaining issues closed out)

• 2011–2012, NIOSH made extensive revisions to their TBDs – most 

complete rewrites. 2
Site Profile Issues and Resolution –

Primary Issue 1

Issue Description: Reconstruction of doses in the absence of 

early health physics, industrial hygiene, and environmental 

records. The absence of pre-1980s records brings into question the ability to 

adequately assign radiation doses during the early years at Pinellas.

– June 2009 WG: SC&A and NIOSH in basic agreement pending TBD 

updates. (Updates released in 2011.)

– October 2011 WG: SC&A is tasked with reviewing additional 

references captured by NIOSH and the effect on external coworker 

modeling.

– November 2012 WG: 

• SC&A concludes that the additional references are extensive and 

provide data from 1957–1995 (i.e., include pre-1980s data).

• Claimant-favorable approach developed assigns the 95th 

percentile of all the data.

• Issue closed by the WG.

3
Site Profile Issues and Resolution –

Primary Issue 2

Issue Description: Potential doses from insoluble metal 

tritides (stable metal tritides [SMTs]) not sufficiently 

addressed. 

– June 2009 WG: Issue was discussed and designated “in 

progress” based on concerns over dose reconstruction (DR) 

approach for special/insoluble tritium compounds (SMTs).

– April 2011: NIOSH updates internal TBD proposing new 

approach to insoluble tritium dose assignment.

– November 2012 WG: NIOSH to evaluate new model for 

consistency and applicability with established methods at the 

Mound Site.

– December 2015: Updated SMT model delivered by NIOSH 

(See file: “dc-pinellastrit-r0.pdf” on the DCAS website).

4
Site Profile Issues and Resolution –

Primary Issue 2 (cont.)

Five Key Aspects of December 2015 SMT model:

1. Resuspension factor: increased from 1E-6 to 5E-5 per meter (same as 

Mound).

2. The use of the highest tritium contamination measurement (1957–1973): 

airborne contamination estimated based highest observed value in monthly 

health physics reports from 1957 to 1973. (Note: Assumed level of SMT 

contamination level is 1 to 2 orders of magnitude higher than the assumed 

values at the Mound Site).

3. Technical adequacy of the method to detect tritium that is bound to 

particulate metal: Contamination swipes utilize cotton ball that was rinsed with 

DI water (counting liquid) and then filtered prior to measurement by liquid 

scintillation counting. Particulate tritium could potentially be trapped in the cotton 

ball and not transfer to the counting liquid. 

4. The magnitude and the extent of potential for tritide contamination at 

Pinellas: SMTs only handled in areas where tritium was handled, and all tritium 

workers were monitored via urinalysis. Model only applied to those with tritium 

bioassay (i.e., coworker intakes not applied to unmonitored workers).

5. Choice of solubility type for the metal tritides present: Assumes all SMT 

intakes are Type M or Type S depending on which is favorable to the individual 

claimant. 5
Site Profile Issues and Resolution –

Primary Issue 2 (cont.)

SC&A White Paper Response (February 2016):

• Review contained 7 observations and 1 finding. (Note: sole finding was withdrawn 

after NIOSH clarified that worker exposures are assigned for 2,600 hours/year.)

• February 2016 WG:

– Discussions focused mainly on the applicability of the sample method (NIOSH 

Item 3), and the documentation supporting prompt cleanup of spills and 

contamination that evidenced a strong health physics program (SC&A 

Observations 4–6).

– SC&A and the WG concurred that the NIOSH model is sufficiently accurate and 

claimant favorable. The WG accepted the SMT model and motioned to put 

Issue 2 into abeyance until the TBD is revised.

– A remaining SC&A concern pertains to the treatment of organically bound tritium 

(OBT). NIOSH responded that OBT behaves more like an insoluble particulate 

than tritiated water (HTO) and is subsumed in the SMT dose. The next TBD 

revision will include a discussion of how intakes of tritides, OBT, and HTO are 

addressed individually. 

6
Site Profile Issues and Resolution –

Primary Issue 3

Issue Description: Minimum detectable concentrations (MDCs) 

and uncertainties for plutonium (Pu) and bioassay measurements 

are inadequately addressed in the TBD.

– Potential exposure to Pu could not be ruled out early in the issues 

resolution process. Discussed at the June 2009 and October 2011 

WG meetings as well as worker interviews.

– Became clear the only source of potential intake was from handling 

newly received triple encapsulated radio-thermal generators (RTGs).

• Surface contamination did not exceed 200 dpm (the rejection level).

• NIOSH calculations show that to receive even 1 mrem annual dose would require 

handling thousands of RTGs per day.. 

– Therefore, no significant source of exposure to Pu-238 has been 

discovered.

– Revision 2 of the internal TBD has removed all Pu discussion. 

However, If evidence of a positive exposure is discovered, 

NIOSH will need to develop a DR methodology.

7
Site Profile Issues and Resolution –

Primary Issue 4

Issue Description: Assessment of personnel badging 

policy during early years needs further review.

– This was a concern early in the issues resolution 

process, when the Pinellas badging policy was not well 

understood. 

– Discussed at the June 2009 WG meeting: 

• Possibility of cohort badging was a concern early in issues 

resolution process.

• Later clarified that the health physics program monitored 

those with exposure potential and there was no cohort 

badging. (Note: The current DCAS coworker model 

assigns the 95th percentile whole-body dose to all 

unmonitored workers and so obviates this issue.)

8
Site Profile Issues and Resolution –

Primary Issue 5

Issue Description: Problems with personnel dosimetry

– June 2009 WG: SC&A’s main concern was that a claimant-favorable 

yet scientifically based limit of detection (LOD) for external dosimetry 

be applied.

– TBD Revised in 2011: Table 6-9 included additional LOD information.

– November 2012 WG: Sub-issue of 10 mrem LOD versus SC&Arecommended 20 mrem remains open. NIOSH was to look into the 

scientific basis supporting an LOD of 10 mrem.

– SC&A concerned that that while 10 mrem is probably acceptable for 

30–250 keV photons, it might be too low for the higher energy 

gamma spectrum from an RTG source (“spectral hardening” of 

photon emissions due to triple encapsulation).

– February 2016 WG: Lengthy discussion – WG agreed to hold a 

technical call with a recognized expert in film badge dosimetry. That 

call took place on February 26, 2016.

9
Site Profile Issues and Resolution –

Primary Issue 5 (cont.)

– For high-energy gammas, optical density (OD) was converted 

according to a step function (not Gaussian). The minimum 

increment on the densitometer corresponded to 6 mR (doses 

increase by 6, 12, 18...mR).

– The “minimum reportable dose” (M) of 10 mR not defined by a 

statistical basis; Landauer adopted the convention that doses 

less than 10 mR were not significant – so 9 mR or less was 

treated as 0, 10 to 14 treated as 10, 15 to 24 as 20, and so forth. 

– DOELAP accreditation guidelines for lower limit of detection 

(LLD) based on Poisson statistics, such that Type 1 and 2 error 

rates (false positive and false negative, respectively) were both 

controlled at 5 percent. Film for high-energy exposure has a LLD 

of 12–14 mR; thus, 95% of time will get 10 or 20 when exposed 

to 12.

– Based on the foregoing, SC&A recommended that Issue 5 be 

closed. At the March 1, 2016, WG meeting, the WG motioned 

to close Issue 5.

10
Site Profile Issues and Resolution –

Primary Issue 6

Issue Description: The decontamination and decommission (D&D) 

era of Pinellas operations is not sufficiently addressed.

• First discussed at June 2009 WG meeting.

• November 2012 WG: Subject Matter Expert (SME) from January 2012 

interviews indicated that all the contract employees were monitored by 

Pinellas RadSafe before, during, and after the D&D operations. Issue 

remained open pending NIOSH receipt of confirmatory D&D monitoring 

records from Albuquerque.

• February 2016 WG: NIOSH has exhaustively captured 5,161 additional 

references, including the requested records from Albuquerque. 

Accordingly, the WG had placed this issue in abeyance until delivery of 

the Sandia National Laboratories (SNL) finding aid.

• March 2016 WG: SNL finding aid found not useful – NIOSH has likely 

exhausted available monitoring records for the period in question. That, 

in combination with the SME interview, provides a strong weight of 

evidence argument that DR is feasible during the D&D period. 

• The WG motioned to close Issue 6 at the March 2016 meeting. 11
Site Profile Issues and Resolution –

Primary Issue 7

Issue Description: Missing internal dose estimation 

methods for unmonitored workers, e.g., maintenance 

and support personnel, not provided. 

– Discussed at the June 2009 WG meeting. 

– Internal TBD update addresses SC&A’s concerns: 

• NIOSH “whole-body dose” coworker model includes a 

tritium component in addition to neutron and external 

gamma dose assigned at the 95th percentile. 

• There is currently no documented plutonium exposure 

potential (Issue 3, above).

• Secondary Issue 2 (below) regarding Ni-63 and C-14, 

addresses other aspects of Issue 7.

12
Site Profile Issues and Resolution –

Primary Issue 8

Issue Description: Potential for missed dose for 

depleted uranium (DU)

– June 2009 WG: Issue was discussed.

– Cutting of DU beds took place at the GEXM facility 

in Milwaukee, Wisconsin, not at Pinellas. Therefore, 

there was no DU exposure potential at Pinellas.

– The WG moved to close Issue 8.

13
Site Profile Issues and Resolution –

Primary Issues 9–11 and Secondary Issue 1

Issue Description: All primary issues and the secondary 

issue relate to occupational medical dose:

– Primary Issue 9: The TBD fails to adequately define and 

assess occupational medical exposure.

– Primary Issue 10: Techniques and protocols increase 

uncertainty of dose conversion factors (DCFs) listed in the 

TBD.

– Primary Issue 11: Frequency and type of x-ray exposure is 

uncertain.

– Secondary Issue 1: Additional factors contribute to 

uncertainties related to occupational medical exposures.

14
Site Profile Issues and Resolution –

Primary Issues 9–11 and Secondary Issue 1 

(cont.)

– June 2009 WG: Issue is discussed.

– Revision to occupational medical dose made after 

the October 2011 WG meeting. 

– SC&A’s subsequent focused review of the TBD 

revision satisfied our concerns regarding Issues 9–

11 and Secondary Issue 1.

– 11/19/2012 WG meeting (p. 54): Formally closed 

Issues 9–11 and Secondary Issue 1.

15
Site Profile Issues and Resolution –

Secondary Issues 2–8

Issues “Closed” based on resolution of the related 

primary issues.

– Secondary Issue 2: Inadequate descriptions for certain plant 

operations

• Ni-63 and C-14 aspects in abeyance as of June 2009 pending addition of 

new information to the TBD (revised April 2011). Secondary Issue 2 and 

DU issue (Primary Issue 8) are no longer relevant and so are closed.

– Secondary Issue 3: Perimeter tritium monitoring stations

– Secondary Issue 4: Inadequacy of the external TBD to 

address uncertainty.

• Secondary Issues 3 and 4 both put in abeyance in June 2008 

pending additional information incorporated into environmental 

TBD revision (released July 2011).

16
Site Profile Issues and Resolution –

Secondary Issues 2–8 (cont.)

– Secondary Issue 5: Rejection of plutonium bioassay results 

based on plutonium-238-to-plutonium-239 ratios, and nondetectable plutonium-239

– Secondary Issue 6: Plutonium solubility

• Secondary Issues 5 and 6 were both completed with the 

disposition of the primary issue (See Primary Issue 3).

– Secondary Issue 7: Assumptions relative to unmonitored 

workers

• This secondary issue was completed with the disposition of 

Primary Issues 4, 6, and 7.

– Secondary Issue 8: Assumptions relative to minimum 

detectable level adjustments to dosimetry for missed dose

• Closed – language clarified in revision to external dose TBD 

(released August 2011).

17
Summary Conclusions

• SC&A and the Pinellas Work Group agree that 

all of the primary and secondary issues raised in 

SC&A’s site profile review have been adequately 

addressed and resolved.

• Primary Issue 2 is in abeyance until NIOSH 

delivers a revision of the internal dose TBD.

• The Work Group recommends closure on 

remaining issues.

18
Questions?